COASTAL HABITAT DEVELOPMENT IN THE 

 DREDGED MATERIAL RESEARCH PROGRAM 



Hanley K. Smith 1 



Waterways Experiment Station 

 U.S. Army Corps of Engineers 

 Vicksburg, Mississippi 39180 



INTRODUCTION 



The Dredged Material Research Pro- 

 gram (DMRP) is being conducted at the 

 Corps of Engineers Waterways Experiment 

 Station at Vicksburg, Mississippi. As 

 manager of the Habitat Development Pro- 

 ject, I plan, manage, and carry out the 

 habitat development aspects of DMRP. 

 Realizing your differing levels of ac- 

 quaintance with the program, I will pre- 

 sent an overview of the DMRP and then 

 concentrate on the habitat development 

 aspects. See Table 1 . 



Dredging the navigable waterways of 

 the United States is important to the 

 Nation's economy and vital to creating 

 and maintaining the channels, harbors, 

 and associated facilities that accommo- 

 date the large volume of domestic and 

 foreign waterborne commerce. The primary 

 purpose of most of this dredging is to 

 maintain a designated channel or area at 

 a predetermined water depth by removing 

 bottom accumulations. These accumula- 

 tions are the result of discharges and 

 erosion, transport, and deposition often 

 influenced by storms and flooding and 

 augmented by man's actions. 



Principal responsibility for navi- 

 gation facility maintenance and improve- 

 ment is vested in the Corps of Engi- 

 neers. With its own equipment or by con- 

 tract, the Corps periodically dredges 

 thousands of kilometers of waterways and 

 hundreds of commercial port facilities 

 and small boat harbors assigned to it by 

 Congress for maintenance. The annual 

 costs of waterways maintenance are 

 approaching $250 million and annual 

 maintenance dredging volumes exceed 

 214,100,000 m 3 (280,000,000 yd 3 ). The 



1 



This same report was presented at the 

 42nd North American Wildlife Conference. 



new work portion approximates $50 mil- 

 lion and 61,200,000 m 3 (80,000,000 yd 3 ) 

 annually. 



The large volumes of dredged mater- 

 ial often present extraordinary disposal 

 problems. In the past, economics was the 

 almost exclusive criterion used in de- 

 termining disposal location and method. 

 However, during the past decade, envi- 

 ronmental impact has become a signifi- 

 cant criterion and, from a practical 

 standpoint, the one controlling many 

 dredging projects. Although limited, 

 some procedures and technology do exist 

 and are being used to avoid or reduce 

 adverse environmental impacts; however, 

 the real problem lies elsewhere. With 

 few exceptions, the state of knowledge 

 and site-specific studies have failed to 

 provide definitive information on what 

 constitutes an adverse impact caused 

 either by nature of the material or the 

 mode of disposal. Hence, opinions and 

 actions regarding dredging and disposal 

 often are based almost entirely ofi fears 

 of unknown consequences rather than 

 facts; decisionmakers have had no way to 

 quantify effects or determine alterna- 

 tives for rational solutions to pro- 

 blems. 



To better depict the scope of the 

 dredging effort and its potential envi- 

 ronmental impact throughout the conti- 

 nental United States, it is necessary to 

 understand that annual dredging require- 

 ments by Corps Districts vary consider- 

 ably. The largest volume, which is 

 nearly 151,470,000 m 3 (198,100,000 yd 3 ), 

 is dredged in the Lower Mississippi Val- 

 ley Division, while one of the smallest 

 requirements is the New England Divi- 

 sion's 1,836,000 m 3 (2,401,000 yd 3 ). 

 Dredging costs, however, present an en- 

 tirely different picture. Although the 

 national average cost per cubic yard is 

 still well under $1, geographically the 



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